Rotary engine



Sept. 16, `1958 G. E. MALLlNcKRoD-r 2,852,006

ROTARY ENGINE 4 Sheets-Sheet 1 Filed sept. 25. 1957 Sept- 15, 1958 G. E. MALLINCKRoD-r 2,852,006

ROTARY ENGINE 4 Sheets-Sheet 2 Filed Sept. 25, 1957 Sept- 16 1958 G. E. MALLlNcKRoDT 2,852,006

ROTARY ENGINE Filed Sept. 25, 1957 4 sheets-sheet s Sept. 16, 1958 G, E. MALLlNcKRoDT ROTARY ENGINE 4 Sheets-Sheet 4 Filed Sept. 25, 1957 ROTARY ENGINE George E. Mallinckrodt, St. Louis, Mo., assignor to Elliot Enterprises, Incorporated, St. Louis, Mo., a corporation of Missouri Application September 25, 1957, Senal No. 686,174

11 Claims. (Cl. 12311) This invention relates to rotary engines of the type in which several rotating systems (having alternating pistons) interchange angular momentums during certain compression and reverse-locking events, and between which systems certain expansion events cause the systems to overrun one another alternately to supply power to a shaft through power integrating means, being an improvement upon the construction shown in my United States patent application Serial No. 625,978, filed December 3,

195 6, for Rotary Engine.

Among the several objects of the invention may be noted the provision of means for transferring momentum between said rotating systems by employment between them of a pressure-operated clutch in order to aid momentum transfer during a gaseous collision or compression event; the provision of a simple fluid-operated friction clutch for the purpose; the provision of means of the class described wherein the clutch is caused to connect and release the rotating systems by the action of simple hydraulic means; and the provision of apparatus of this class wherein the timing of the hydraulic means for clutch operation is brought about by simple porting of the rotating systems and the stationary parts in which they rotate. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of which will be indicated in the followings claims.

ln the accompanying drawings, in which one of various possible embodiments of the invention is illustrated,

Fig. l is a partial longitudinal jogged section of an engine embodying the invention, being taken on line 1-1 of Fig. 2, some of the parts at the left, which are the saine as parts shown at the right, being omitted;

Fig. 2 is a cross section, taken on line 2 2 of Fig. l,

me cngine being shown in an intermediate or neutral' position of rotor parts;

Fig. 3 is a cross-section taken on line 3--3 of Fig. 1;

4 is a skeleton diagram of parts corresponding to their neutral positions shown in Fig. 2, wherein one rotor is advancing upon the other rotor, the latter being reverse locked;

Fig. 5 is a view similar to Fig. 4; showing further advance of the one rotor relative to the reverse-locked rotor;

Fig. 6 is a view similar to Fig. 5 but showing further advance of the one rotor and retreat of the other from reverse-locked position;

Fig. 7 is a view of a position of parts similar to Fig. 6, except that the rotor positions have been interchanged;

Fig. 8 is a diagrammatic developed View on line 8-8 of Fig. 2; and,

Fig. 9 is a View similar to Fig. S, the parts being shown being in a further advanced position.

The stippling shown in the drawings is arbitrary and for the purpose of diagrammatically distinguishing one States aten@ ICC connected set of pistons A, B, C, D on rotor 31 from an unstippled set of connected pistons, W, X, Y, Z on rotor 29. In the diagrammatic Figs. 4-7 the unstippled pistons W, X, Y, Z on rotor 29 are dotted as a further distinction.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring now more particularly to Fig. l, there is shown at numeral l a stationary ring to which supporting cylinder heads 3 and 5 are attached by means of through bolts 8. Parts 1, 3 and 5 form an annular or toroidal cylinder generally indicated by 7. The ring 1 is provided with a jacket 9 to form a water-cooling space 11. The cylinder heads or supports 3 and 5 are formed with necks 13 and 15,respectively, in which are pressfitted, fixed anged liners 17 and 19, respectively, held in proper axial press-fitted positions by adjusting nuts 2l and 23, respectively threaded to the necks 13 and 15. The flanges of the liners are numbered 25 and 27, respectively, their inside faces being fixed and substantially flush with the inside faces of the cylinder heads 3 and 5. Thus the liners become parts of the heads or supports 3 and5.

Located between the flanged portions 25 and 27 are abutting rotors `29 and 31. These have hollow quills 33 and 35, respectively, extending through and out from said liners 17 and 19. Within the quills 33 and 35 are bearing sleeves 37 and 39, on a power shaft 41 extending axially through the machine. These sleeves 37 and 39 form bearings for the rotor quills 33 and 35, respectively.

Carried on the rotor 31 and extending in an axial direction over the outside of the rotor 29 are power pistons A, B, C and D (Fig. 2). Carried on the rotor 29 and extending in an axial direction over the outside of the rotor 31 are power pistons W, X, Y and Z. The power pistons A, B, C, D on rotor 31 interdigitate with the power pistons W, X, Y, Z on rotor 29 and all of them are within the annular cylinder 7. Ring sealing means 2 are employed in each piston, the de tails of which are of no concern to the essentials of the present invention and they are therefore shown diagrammatically by hatching. Thus power cylinder 7 is formed on the outside by the ring 1, on the ends by the heads 3 and 5, and on the inside by the circular portions of the rotors 29v and 31 that lie just within their pistons. i

In the heads 5 are provided inlet ports I and exhaust ports E. Conventional fuel carbureting means such as a carburetor or fuel injector (not shown) is connected with `the inlet ports I. Ignition means, countersunk in the head 3, are shown at G, preferably of the continuous, so-called glow-type, having a conventional exciting circuit requiring no electrical timing means. If, as may be, a spark-type ignition is used, then suitable timing will be required in the exciting circuit. The glow-type is employed for purposes of description.

Fastened to the cylinder heads 3 and 5, respectively, are supporting frameworks 43 and 45, supporting inwardly directed cam tracks 47 and 49, respectively. The following description of reversealocking parts operative with cam track 49 on the right-hand end of the machine (Fig. l) is identical with the description applicable to the reverse-locking parts operative with cam track 47 on the left-hand end of the machine. The numbering of these parts will therefore be identical and the one description will apply to both sets of such parts. As will be seen from Fig. l, some of the parts at the left-hand end of the machine are not shown, in order that the scale of Fig. l may be as large as possible in the space available; but it will be understood that the parts not shown at the left-hand end of the machine are the same 3 in form and operation as those shown on the righthand side.

Referring then to the right-hand side of the machine as shown in Fig. 1, quill of the rotor 31 has attached thereto ya hub 51. The corresponding hub 51 at the lefthand end of the machine is attached' `to quill 33 of rotor 29. Lock nuts S3 are used for such purposes. Extending from each hub 51 are lugs 55, in which are rotary pintles 5'7. Clamped to each pintle 57 is an L-shaped follower link 59, one arm of which (Fig. 3) is split, as shown at 61, and provided with a clamping bolt 63 for clamping each arm fast to its pintle. At the end of the other arm of each follower link 59 is a roller follower 65, engageable with cam track 49. Springs 67 maintain engagement between the follower rollers 65 and the cam track 49. Each spring 67 has a bail 69 engaging its respective lug and anchors 71 on the ends of its respective pintle 57, and is wound with tension in the appropriate direction to effect said engagement.

The cam track 49, for the number (eight) of power pistons Shown, is of generally square form, having four flats 73 joined by four corner llets 75. This arrangement permits free rotation of the respective hub S1 with its lugs 55 in one direction (clockwise in Fig. 3, as shown by the curved dart F). When the parts are in or near the positions shown in Fig. 3, reverse rotation is prevented. This is referred to herein as a reverse-locked position. The reason for the reverse-locking effect is that each compression thrust H is quite close to a perpendicular position relative to its respective flat 73 at a point adjacent its respective llet 75. This, in view of the tension wound into its respective spring 67, will not allow anticlockwise rotation of the respective fol lower link S9. It is to be understood that there is a small range of positions near perpendicularity of the vectors H within which range reverse locking can occur. This obviates a harsh impact effect upon reverse locking, resulting in what may be designated a soft reverselocking action, which is conducive to long roller and cam track life. The stated range is measured by only a few degrees.

During clockwise rotation of the respective hub 51 and lugs 55 (Fig. 3), the follower links oscillate in and out around their pintles 57 as the roller followers 65 traverse the cam. 1t will be understood that, although Fig. 3 shows the reverse-locking cam and follower arrangement on the right-hand end of the machine, the one on the left-hand end involving cam track 47 is the same in form and the cam tracks 47 and 49 are in the same positions relative to the various parts of cylinder 7. Since the respective hubs 51 are attached to the respective quills 3S and 33 of the respective rotors 31 and 29, the rotors, and their attached power pistons (A, B, C, D) and (W, X, Y, Z) respectively have certain reverse-locking positions. The reverse-locking position for rotor 31 is shown in Figs. 2, 4 and 5; that for rotor 29 in Fig. 7. The direction of free rotations for both rotors will accord to downward piston movements at the top of Fig. 1 and upward piston movents at the bottom. This corresponds to clockwise movement in Fig. 3 and anticlockwise movement in Fig. 2. The reverse-locking direction is anticlockwise in Fig. 3 and clockwise in Fig. 2.

Bolted to each hub S1 (see bolts 77) is a spacer ring 81 and a iywheel 79. The bolts also hold the flanges 83 of inner and outer anchoring sleeves 85 and 87 for clamping one end of a helical drive spring 89. The outer sleeve 87 is split and provided with a nut 91. When the nut 91 is run in on the sleeve 87, one end of the spring 89 is gripped. The other end of the spring 89 is anchored between sleeves 93 and 95, the outer one of which is also split for reception of a nut 97 for gripping purposes. The right hand ends 99 of the anchoring sleeves 93 and 95 are pinned to the shaft 41 (see pin 191, for example).

Shaft 41 is threaded, such as shown at 103, for the reception of a nut 10S which forms a shoulder spaced from the end of the respective quill (3S in this case). In the space is located an end thrust bearing 107. The iiywheel and spring driving apparatus just described are duplicated at the left-hand end of the machine, although only partly shown in Fig. l. Thus rotor 31 is connected at the right to shaft 41 through one spring 89 shown in Fig. l, and is connected at the left to shaft 41 through another spring 89 which does not appear in Fig. l, but is identical to the spring 89 and its connections as shown and described.

Reverting to the central portion of the machine adjacent section line 2-2 of Fig. 1, and to Fig. 2, the abutting ends of the rotors 29 and 31 are cup-shaped and together form a circular cavity 6 within the liners surrounding shaft 41. ln this cavity 6 are two solid clutch rings 16 and 12, located in rotors 29 and 31. respectively. These rings are preferably composed of a plastic such as Teflon, nylon or the like, although it is within the purview of the invention that they may be composed of other materials, including metals.

Each ring 10 and 12 has a close sliding t in the cup shape of its respective rotor 29 or 31 so as to function as a piston therein. Each is slidably carried upon a plurality of (three) pins. The pins for ring 10 are numbered 14, and those carrying ring 12 are .numbered 16. Pins 14 are anchored in openings in rotor 29, and pins 16 are anchored in openings in the rotor 31. The rings 10 and 12 are provided with coextensive radial grooves 1S forming radial channels. Three channels result (Fig. 2), two of which have been rotated into the plane of Fig. 1 for illustrative purposes. The resulting radial channels 13 connect with an inner peripheral channel 25) cut in shaft 41 and an outer peripheral channel 22 formed by adjacent quarterround grooves cut into rotors 29 and 31. The channel 2t) is connected by a passage 24 with a peripheral groove 26 of the shaft which is in communication with an outlet 28 through sleeve 37 and quill 33. The outlet 28 may be connected to a fluid sump (not shown).

The channel 22 has opposite sides in communication with grooves 30 and 32 in the stationary flanges 25 and 27, respectively, this being accomplished by passages 34. The grooves 30 and 32 are externally ported (see passages 36 and 38, respectively). Passages 36 and 38 may also be -connected with said sump. The purpose of this arrangement is to provide for escape of leakage fluid from between the clutch rings 1@ and 12 radially outward and inward when the rings are forced together, as will be described. Otherwise such leakage fluid might interfere with proper clutch engagement.

In order from time to time to effect clutch closure by forcing together the rings 10 and 12 in an axial direction, pressure inlet porting means is provided. This, in the case of rotor 31 (Figs. 1 and 2) is constituted by four inlet ports 40, all of which are shown in Fig. 2 and one of which is indicated in the plane of the section at the top of Fig. l. These ports 4t) are in stationary member 19. Each is supplied with a suitable hydraulic huid under pressure through an inlet 42, one of which inlets has been shown in the plane of the section at the top of Fig. l. All are shown in Fig. 2y and are located in the stationary member 5.

At numerals 44 are shown four stationary outlet or release ports in the member 19 which are connected with the atmosphere through four outlet passages 46. ln rotor 31 are four segmental transfer ports 48. These transfer ports traverse the inlet pressure ports 4G and the release ports 44, the action of which will be described below. Ports 40, 42, 44, 46 and 48 also appear in Figs. 8 and 9. Similar transfer ports 48 are located in the rotor 29; similar inlet ports 40 are located in the member 17, bcing connected with similar pressure inlet ports 42 in the member 5. Also, similar release ports 44 are located in the stationary member 17, connected with the atmos- Law assaooe phere through similar connecting passages 46. These do not show on Fig. 2, being in front of the section 2 2, but examples appear in Figs. l, 8 and 9. All appear on the diagramamtic Figs. 4, 5, 6 and 7, namely, inlet ports 40, 40', outlet ports 44, 44', and transfer ports 48 and 48. However, in these diagrammatic figures the ports 40', 44 and 48 have been shown on a radius which is smaller than the radius of the ports 4h, 44 and 48 in order to avoid confusion in illustration and the description to be given of operation in terms according to said Figs. 4, 5, 6 and 7. The use of this convention has resulted in Figs. 4, 5, 6 and 7 in the ports 4S appearing shorter than the ports 48, and the distance between ports 40 and 44' as being less than the distanc between ports 40 and 44. How ever, the controlling angles subtended by the spacing of ports 48 and 44 and the lengths of ports 48' have been maintained the same as the corresponding angles of ports 40, 44 and 48. It will therefore be understood that the ports 40', 44', 48', as shown in Figs. 4, 5, 6 and 7, are actually on the same radius as ports 40, 44, 48 and subtend equal angles, as is apparent from Figs. l, 8 and 9.

Referring to Figs. 2 and 4-7, operation is as follows, keeping in mind that the rotary directional dart F of Fig. 3 will appear in the reverse direction, as shown in Figs. 2 and 4-7.

Starting with the parts as shown in Figs. 2 and 4 (the latter being diagrammatic), the rotor 31, carrying pistons A, B, C, D, is taken to be in reverse-locking position (see the reverse-locked position of the followers S9, 65 on the cam track 49 in Fig. 3). An expansion (explosion) event is occurring both between pistons A and W and between pistons C and Y; an exhaust event is occurring both between pistons W and B and between pistons Y and D; a suction or fuel injection event is occurring both between pistons B and X and `between pistons D and Z; and a compression event is occurring both between pistons Z and A and between pistons X and C. Under these conditions, all of the pressure inlet ports 40 and 40 are cut oif, so that no pressure exists behind (to the left or right) of either clutch rings 10 or 12. Any pressure that theretofore existed behind (to the left or right) rings 10, 12 has been released in a manner which will appear. Consequently, the rotors 29 and 31 are freely movable one with respect to the other, insofar as the gaseous suction, compression, expansion and exhaust events between the pistons A, B, C, D, W, X, Y, Z will permit, taking into account also the reverse-locking action of the parts such as shown in Fig. 3.

Returning to Fig. 4, it will be observed that the segmental ports 48 in rotor 31 (strippled to show that they connect with pistons A, B, C, D on rotor 31) are stationary and connected with the release ports 44, which are also stationary. Rotor 29, carrying pistons W, X, Y, Z, is overtaking the stationary rotor 31. Transfer ports 48 on rotor 29 are advancing toward but have not arrived at the pressure ports 46. Ports 48' in rotor 29 are dotted in Figs. 4-7, for further distinguishing them from the stippled transfer ports 48 in rotor 31.

Referring to Fig. 5, it will be seen that the reverse-` locked position of the rotor 31 with its pistons A, B, C, D Vand transfer ports 48 has not changed. However, rotor 29 has advanced upon rotor 31 to increase the compression between pistons A, Z and X, C by reducing the compression space between the members of the pairs, respectively, to the amounts shown. As this occurs, the transfer ports 4S are effecting registry with the pressure inlet ports 40', which initiates introduction of hydraulic uid under pressure to the left of the clutch ring 10, forcing it into frictional engagement with the clutch ring 12. Any duid that may be located between these rings is squeezed out to escape via the grooves 2i) and 22 and their connected outlets 24, 28 and 34, 36, respectively. Thus a clutching lockup is initiated between the rotors via the clutch rings 10 and 12, which are now being pressed together. The lockup force increases as registry be tween transfer ports 48 and pressure inlet ports 40'y develops, and this lockup is maintained during the angle of action determined by the angle of registry. After and during full lockup, the rotors are mechanically locked together for synchronous movements.

After the pistons Z, W, X, Y of rotor 29 have approached the power pistons A, B, C, D, respectively of rotor 31 to a distance somewhat closer than the distance shown in Fig. 5, the rotors become locked up and the pairs of pistons Z, A; W, B; X, C, and Y, D move synchronously. Therefore any excess momentum in-the parts connected with rotor 29 is delivered to the parts connected with rotor 31, the two moving together synchronously after the event shown in Fig. 5 and up until the event shown in Fig. 6, the spacing between the power pistons being as illustrated in Fig. 6. This moves rotor 31 from its reverse-locked position. Note also, referring now to Fig. 6, that the prior reverse-locking explosion pressure ahead of pistons A and C has been spent. The compressed charge trapped between pistons A, Z on the one hand and X, C on the other hand is now exposed to the ignition devices G, thus igniting the compressed charge between these pistons. At this time the movements yof transfer ports 4S have brought them so that they are leaving registry with the pressure inlet ports 40 while coming into registry with the release ports 44. The result is a release of the clutch rings 10 and 12 from one another so that the rotors 29 and 31 may again move independently. During the time that the explosion pres sure is building up, the pistons W, X, Y, Z of rotor 29 move up into reverse-locking position, as illustrated in Fig. 7. When the explosion pressure reaches maximum, reverse locking occurs while the rotor 31 is driven forward under a power stroke.

In Fig. 7 the transfer ports 48 bear the same angular relation to the pressure inlet and release ports 40 and 44 as transfer ports 48 bore to pressure inlet and pressure release ports 48 and 44 in Fig. 4. In other words, the locking sequence will not repeat itself as rotor 31 (having on it power pistons A, B, C, D) overtakes reverse-locked rotor 29 (having on it power pistons W, X, Y, Z). As the overtaking action proceeds from Fig. 7, ports 48 will rst come into register with pressure inlet ports 40, followed by locking up the rotors for synchronous action at the desired maximum compression between their power pistons D, Z, and B, X, respectively, and they will move synchronously until the minimum conipression space between these pairs of pistons is exposed to the ignition devices G. At that time the transfer ports 48 will be leaving registry with the pressure inlet ports 46 and connecting with the pressure release ports 44. The only difference in the second sequence of events is that the clutch ring 12 will be pressed from right to left against clutch ring 10 during closing action, rather than the closing action occurring from left to right as was the case in the rst cycle of action shown as starting in Fig. 4. After the second sequence of action additional sequences occur, during which the clutch rings 10, 12 reclose and reopen. both rotors 29 and 3l the clutch closes and reopens eight times, in order to synchronize the actions of the rotors during the eight compression events that occur. Thus synchronization between the rotors 29 and 31 is temporarily maintained during eight different equally timed intervals for each turn.

The developed section of Fig. 8, taken on line 8 8 of Fig. 2, shows how all of the transfer, pressure inlet and release ports are related. That is to say, the rotor 31 is in its reverse-locked position in which the clutch release action afforded by movement of transfer port 48 across release port 44 is in existence. The clutch rings 10 and 12 are at this time (Fig. 8) not being pressed together and rotor 29 is overtaking rotor 31. Its ports 48 have not yet come into registry with the pressure inlet ports 40.

Thus for each complete turn of Fig. 9 shows the parts illustrated in Fig. 8 moved to a position corresponding to one between the events shown in Figs. and 6. In this case, rotor 31, carrying pistons A, B, C, D, is starting to move from reverse-locked position under inuence of coupling action between rotors 29 and 31. At this time the rings l0 and 12 are pressed together by fluid pressure entering from the left of Figs. l and 9. The locking action occurs by reason of registry of the transfer ports 4S with a pressure inlet port 40.

As each rotor is intermittently driven under an expansion event and moves its follower system Si, 55. 57. S9, 65 along with its flywheel 79, it drives the shaft 41 by winding up its respective connecting spring 89, the other spring S9 connecting the other rotor system with the shaft unwinding. The springs therefore form means whereby alternately energy is delivered from the respective rotors to the common shaft 41, and permit alternate overrunning of one rotor with respect to the other. In effect they integrate motion at the shaft received from the rotors.

Although the clutch rings l() and l2 are stated to be composed of a plastic material such as Teilen or nylon, which have favorably operating friction surfaces in the presence of hydraulic fluids, other materials may be used for the purpose. Also, these rings, if composed of other materials, may be suitably faced with suitable frictional material on their adjacent pressure engaging surfaces. The hydraulic lluid employed is preferably of the lubricating type, for example engine oil, or such as is used in automatic transmissions.

A suitable pump driven by the engine itself, and a hydraulic circuit, may supply the pressure at the inlet ports 4G and 42', and as above stated suitable connections are made between the outlets 2S, 46 and de' and a sump supplying the pump. These circuit parts are not shown and may be any one of a number of conventional ones available for the purpose.

lt is to he noted that the type of rotary engine to which the invention applies is sometimes referred to in the art as an alternating piston engine, meaning that groups of interdigitating power pistons on rotors in a toroidal or annular cylinder move alternately in carrying out thermodynamic cyclic processes. The term alternating is also used in the sense that the pistons of one rotor alternate in position with respect to the pistons on the other rotor.

The engine may also be described as of the so-called unidirectional free piston variety in the sense that the motion of the cooperating pistons relative to one another has no positive constraint except through the clutch action at intervals.

in view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

l. A rotary engine comprising an annular cylinder, a support therefor, relatively movable rotors, pistons on said rotors interdigitated in said cylinder adapted upon relative movements of the rotors to pass` through compression events, clutch elements respectively connected to the rotors adapted to be engaged to synchronize the rotors and to be disengaged to release the rotors for relative movements, and clutch control means operated by and in accordance with the motions of the rotors with respect to said cylinder adapted temporarily to engage said clutch elements and synchronize said rotors during said compression event.

2. A rotary engine made according to claim 1, wherein said rotors are oppositely formed to provide a circular cavity, and wherein said clutch elements are constituted Q. La

by nonmetallic fluid pressure-operated pistons in said cavity movable toward direct contact with one another by endwise axial fluid pressure for clutch engagement and disengagement upon release of said pressure, said cylinder support having fluid pressure inlet and release ports, said rotors having transfer ports traversing said pressure and release ports adapted to apply and release fluid pressure on said clutch pistons for said engagement and disengagement.

3. A rotary engine made according to claim l, wherein said rotors are oppositely formed to provide a circular cavity, and wherein said clutch elements are constituted by adjacent fluid pressure-operated pistons in said cavity movable toward one another by endwise axial fluid pressure for clutch engagement and disengagement upon release ot said pressure, said cylinder support having fluid pressure inlet and release ports, said rotors having transfer'ports traversing said pressure and release ports adapted to apply and release fluid pressure on said clutch pistons for their engagement and disengagement.

4. A rotary engine made according to claim 3, including means providing relief ports adapted for escape of leakage fluid from between the clutch pistons upon approach for engagement between them.

5. A rotary engine comprising an annular cylinder, relatively movable rotors, pistons on said rotors interdigitated in said cylinder adapted upon relative movements of the rotors to pass through suction, compression, expansion and exhaust events, clutch rings respectively attached to the rotors for rotations therewith but axial movements relative thereto and adapted for axial engagement to synchronize the rotors and for axial disengagement to release them for relative movements, and clutch control means operative by and in accordance with the motions of the rotors with respect to said cylinder adapted temporarily axially to engage said clutch rings to synchronize said rotors during a part of said compression event just preceding said expansion event.

6. A rotary engine comprising a support for an annular cylinder, relatively movable rotors, pistons on said rotors interdigitated in said cylinder adapted upon relative movements of the rotors to pass through suction. compression, reverse-locking, expansion and exhaust events, clutch pistons respectively attached to the rotors for rotations therewith but axial movements relative thereto and adapted for axial trictional engagements to synchronize the rotors and for disengagement to release them for relative movements, and hydraulic clutch control means operative by and in accordance with the motions of the rotors with respect to said cylinder adapted tcmporarily to force said clutch pistons into frictional engagement to synchronize said rotors during a part of i compression event just preceding said reverse-locking and expansion events.

7. A rotary engine comprising an annular cylinder having side wall portions, relatively movable rotors having cylindrical cup-shaped abutting portions providing a circular cavity located between said side wall portions, power pistons on the rotors interdigitated in said cylinder and adapted upon relative movements of the rotors to pass through suction, compression, expansion and exhaust events, circular clutch rings in the respective rotors formed and fitted as pistons in said cup-shaped portions of the rotors forming said cavity, the respective clutch rings being attached for synchronous rotation with their respective rotors but axially movable therein for frictional engagement and disengagement to synchronize rotors or permit relative movements between them, pressure inlet and release ports connectting through said side wall portions with the cavity on opposite sides of the clutch rings, said rotors having transfer ports adapted upon rotor movements to move across said pressure and release ports thereby to apply and release pressure to and against said clutch rings frictionally to connect and then to release them to provide temporary synchronization of the rotors as the power pistons pass through a terminal portion of said compression event.

8. A rotary engine made according to claim 7, including grooved relief ports within and outside of the clutch rings adapted for relief of any leakage fluid past the clutch rings into the space between them.

9. A rotary engine comprising an annular cylinder having side wall portions, relatively movable rotors having cylindrical cup-shaped abutting portions providing a circular cavity located between said side wall portions, power pistons on the rotors interdigitated in said cylinder and adapted upon relative movements of the rotors to pass repeatedly through suction, compression, expansion and exhaust events during individual rotations of the rotors, clutch rings in the respective rotors formed and tted as pistons in said cup-shaped portions of the rotors forming said cavity, the respective clutch pistons being axially movable in the cavity but attached for synchronous rotation with their respective rotors, said clutch pistons being adapted for frictional engagement of their adjacent surfaces and disengagement to synchronize the rotors or permit relative movements between them, multiple groups of pressure inlet and release ports connecting through said side wall portions with the cavity on opposite sides of the clutch pistons, said rotors having transfor ports adapted upon rotor movements to effect traverse of said transfer ports across said multiple groups of pressure inlet and release ports thereby repeatedly to apply and release pressure to and under said clutch pistons frictionally to connect and release them for temporary synchronization of the rotors as the power pistons pass through terminal portions of compression events.

l0. A rotary engine comprising a support for an annular cylinder, relatively movable rotors, pistons on said rotors interdigitated in said cylinder adapted upon relative movements of the rotors to pass through suction, compression, expansion and exhaust events, clutch elements, means supporting said clutch elements respectively on the rotors for equal rotations therewith and axial movements relatively thereto, the clutch elements being adapted for engagement upon axial movement to synchronize the rotors and for disengagement to release them for relative movements, and clutch control means operative by and in accordance with the motions of the rotors with respect to said cylinder adapted temporarily to move said clutch elements relatively axially for interengagement to synchronize said rotors during a part of said compression event just preceding said expansion event.

ll. A rotary engine comprising an annular cylinder having side wall portions, relatively movable rotors having cylindrical cup-shaped abutting portions providing a circular cavity located between said sidewall portions, a plurality of power pistons on each rotor interdigitated with one another in said cylinder adapted upon relative movements of the rotors to pass through compression, reverse-locking and expansion events, means adapted to reverse lock each rotor a number of times during its rotation equal to its plurality of pistons, circular clutch elements in the respective rotors formed and tted as pistons in said cup-shaped portions of the rotors forming said cavity, the respective clutch elements being axially movable in the cavity but attached for synchronous rotation with their respective rotors, said clutch elements.

being adapted for frictional engagement and disengagement to synchronize the rotors or permit relative movements between them, groups of pressure inlet and release ports connecting with the cavity on opposite sides of the clutch elements, the number of groups on each side being equal to the plurality of power pistons on a rotor, each of said rotors having transfer ports equal in number to the numbers in each of said groups adapted upon rotor movements to move across said groups of pressure release ports thereby to apply and release pressure to and under said clutch elements frictionally to connect and release them for temporary synchronization of the rotors as the power pistons pass through a terminal portion of said compression event.

No references cited. 

